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fb3a3066d1
For register-rich ABIs (e.g. x86-64 and ARM), QueryInterface's incoming registers are going to look like: arg register 1: |this| arg register 2: the IID of interest arg register 3: the outparam instance pointer Most of our QI implementations call NS_TableDrivenQI, which expects arguments like so: arg register 1: |this| arg register 2: the QITableEntry table arg register 3: the IID of interest arg register 4: the outparam instance pointer So we're going to have to do a register shuffle of the IID and the outparam to be able to load the QITableEntry pointer before calling into NS_TableDrivenQI. This patch reorders the argument list of NS_TableDrivenQI so that the first three arguments match the order that QueryInterface receives them in. Then your typical QueryInterface implementation becomes: - load local |table| - tail-call NS_TableDrivenQI Eliminating the register shuffling reduces text size by 12K on an Android ARM build.
27 lines
729 B
C++
27 lines
729 B
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "nsISupportsImpl.h"
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nsresult NS_FASTCALL
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NS_TableDrivenQI(void* aThis, REFNSIID aIID, void **aInstancePtr,
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const QITableEntry* entries)
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{
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do {
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if (aIID.Equals(*entries->iid)) {
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nsISupports* r =
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reinterpret_cast<nsISupports*>
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(reinterpret_cast<char*>(aThis) + entries->offset);
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NS_ADDREF(r);
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*aInstancePtr = r;
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return NS_OK;
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}
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++entries;
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} while (entries->iid);
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*aInstancePtr = nullptr;
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return NS_ERROR_NO_INTERFACE;
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}
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